The present invention relates to a vertebral osteosynthesis equipment.
A vertebral osteosynthesis equipment includes, in a manner that is well known per se:                at least one rigid rod intended to be extending along several vertebrae, and in general two rods intended to be placed on either side of the spinous processes of the vertebrae;        bone anchoring members, such as screws or laminar hooks, intended for anchoring the rod or rods to the vertebrae to be treated; each bone anchoring member has a proximal threaded pin and a support surface;        connection pieces to be used for connecting the rod or rods to the bone anchoring members, each connection piece having a hole for the engagement thereof on to the proximal threaded pin of a bone anchoring member and a receiving channel for the engagement of an aforementioned rod; and        nuts intended to be screwed on to the proximal threaded pins of the bone anchoring members in order to tighten the connection pieces against the said support surfaces.        
A known device of this type is described in particular in the published patent application No. WO 98/55038; in this device, each connection piece is of the “closed” type, that is to say it has a closed portion for delimiting the said receiving channel for receiving one aforementioned rod. Such a rod can thus only be engaged axially in this channel.
Known equipments also include, in particular as detailed in the published patent applications Nos U.S. 2013/072991 A1, U.S. 2002/169450 A1or FR 2 765 093 A1, devices comprising connection assemblies with each including a connection piece of “open” type, that is to say, having a curved portion that is adapted to only partially enclose a rod as mentioned above, and a mating component piece that, in a closer position relative to the curved portion, makes it possible to close the channel delimited by this curved portion in order to retain a rod engaged in the said channel. The connection piece and the mating component piece are provided with holes for the engagement thereof on to the proximal threaded pin of the anchoring member and comprise positioning means to ensure the positioning of one in relation to the other in a mounting position in which these holes come to be coincident with each other.
The vertebral osteosynthesis equipment according to the aforementioned prior art documents have the disadvantage of not being very easy to implement as implants due to the fact that the connection pieces and the mating component pieces are to be set in place and positioned one after another, at the bottom of the cavity, and because they have reduced dimensions, which make the risk of their escape quite high. The impact of these drawbacks are felt all the more given that the successive assembly and disassembly of the rods and connection assemblies must be carried out in order to test the curvature of the vertebral rods during the surgical intervention so as to assess whether the form and shape of the rods are such as to allow for the desired correction or adjustment to be obtained.